The figure shows how to couple two TTL circuits using an optical coupler to obtain isolation. The circuit is shown in the August 1992 issue of Radio Electronics magazine.
This circuit is from Popular Electronics from the 90's. The circuit discharges the battery with a...
This TTL module can be used in counter and many of them can be cascaded to counts up to 99, 999,...
This circuit prevents damage by accidentally reversing the power supply polarity. The circuit is...